Dual roll paper towel dispensers are advantageous because they permit dispensing from one paper roll and then, once the paper from that paper roll is exhausted, they permit dispensing from a second paper roll held in reserve. A paper towel dispenser that permits sequential dispensing of the rolls is advantageous because it allows a roll to become depleted of paper towel before a custodian or janitor replaces the depleted roll with a new roll. In single roll paper towel dispensers, a custodian may replace a non-depleted paper roll thereby creating waste and added cost. In addition, not all dual roll paper towel dispensers encourage complete consumption of the paper from a paper roll.
One type of dual roll paper towel dispenser includes two rolls of paper towel arranged side by side. This type of arrangement can be referred to as a horizontally arranged dispenser and generally requires that the dispenser occupy a length of wall corresponding to the length of at least two paper rolls. See U.S. Pat. No. 4,260,117. Another type of dual roll paper towel dispenser includes two rolls arranged vertically with respect to each other. Such dispensers can be referred to as vertically arranged dispensers. See U.S. Pat. Nos. 3,288,387; 4,165,138; 4,206,858; and 6,145,779. Certain vertically arranged dual roll paper towel dispensers include a transfer mechanism that permits a paper towel transfer from a depleted primary roll to a secondary roll held in reserve wherein both rolls dispense through the same drive roller and nip roller. Such designs can be difficult to service. For example, in some cases, the custodian may need to move the secondary roll to the primary roll position, and then install a new secondary roll. Because of the complexity, there is an increased chance that the dispenser may not be serviced correctly.
Several electronic dual roll paper towel dispenser designs are available. For example, see U.S. Pat. Nos. 7,354,015; 7,325,768; 7,325,767; 6,695,246; and 6,988,689.